Typo fix; constant name is uppercase
diff --git a/Doc/library/re.rst b/Doc/library/re.rst
index 1259b11..e50a8dd 100644
--- a/Doc/library/re.rst
+++ b/Doc/library/re.rst
@@ -215,7 +215,7 @@
``(?aiLmsux)``
(One or more letters from the set ``'a'``, ``'i'``, ``'L'``, ``'m'``,
``'s'``, ``'u'``, ``'x'``.) The group matches the empty string; the
- letters set the corresponding flags: :const:`re.a` (ASCII-only matching),
+ letters set the corresponding flags: :const:`re.A` (ASCII-only matching),
:const:`re.I` (ignore case), :const:`re.L` (locale dependent),
:const:`re.M` (multi-line), :const:`re.S` (dot matches all),
and :const:`re.X` (verbose), for the entire regular expression. (The